The present invention relates to a portable video lighthead typically used on video cameras. These lightheads may be used, for example, to provide illumination for video cameras used under low light level conditions and light fill situations when overhead lighting or strong sunlight creates dark shadows on the subject.
Portable video lightheads are exemplified by the Mini-Fill lighthead line of Frezzolini Electronics, Inc. of Hawthorne, N.J. They are extremely lightweight at about 12 ounces and have a compact size of 2 by 4.5 inches. They typically operate from any 12 to 14 or 30 volt battery, utilize high efficiency mirror lamps and operate in the range of 20-100 watts. They mount on any video camera, such as those used by the broadcasting industry for televising events.
When used indoors, the Mini-Fill lightheads may be too bright for some purposes. It is therefore desirable to modify the brightness of the Mini-Fill lightheads so that they may be used indoors and yet satisfy the requirements for less obtrusive lightheads.
Further, it is also desirable to maintain the overall brightness selected by the user at a constant level, even as ambient lighting conditions change, as the lighthead battery voltage drops, and as the subject moves closer to or further from the light source.